ADODB stand for ActiveX Data Objects Databases and it is an object model for manipulation of data access drivers. ADODB permit VB and VBA programmer access to ODBC drivers wich drive the database. Your declaration mean that you are creating an object named cnn1 is Connection. A connection is a link between your application and a database. ADODB is a database abstraction library for php Originally based on the same concept as Microsoft's ActiveX Data Objects. It allows developers to write applications in a consistent way regardless of the underlying database system storing the information. The advantage is that the database system can be changed without re-writing every call to it in the application. ADODB is easy to port because all the database dependant code are stored in stub functions without need to port the core logic of the classes. Database performance monitoring and SQL tuning with the performance monitoring classes in ADODB.